Hot Topics in Cancer Risk: Your Most Frequently Asked Questions

With so many studies making headlines on organic foods, sugar and other hot topics, our experts looked at the latest research to answer your most frequently asked questions. This research is ongoing but for now, here is the when it comes to how diet, activity and weight affect cancer risk.

Q. Will organic fruits and vegetables offer more protection against cancer than conventionally grown foods?

A: There is currently no strong evidence to show that organic foods offer added protection against cancer compared to conventionally grown produce. Further research is required. Eating a diet rich in plant foods, including vegetables and fruits, can help reduce the risk of several cancers – whether they are organically or conventionally produced.

Buying organic may make sense for you. But research clearly shows that eating a wide variety of plant foods every day – in addition to being physically active and maintaining a healthy weight — is what really matters. When it comes to lowering cancer risk, the bottom line is: enjoy vegetables, fruits, whole grains and beans however you can – fresh, frozen, canned, conventional or organic. Get them however you can, but get them.

Q: What are genetically modified (GM) foods and do they link to cancer risk?

A: Genetically modified foods are produced from organisms that have had specific changes introduced into their DNA using genetic engineering. There is currently insufficient evidence to conclude that genetically modified foods affect cancer risk.

Q: How does coffee link to cancer risk?

A: Evidence shows that drinking coffee can reduce the risk of endometrial and liver cancers. Yet there are many unanswered questions, such as how much is the optimal amount to drink and how to maximize the preventative benefits. There is insufficient evidence to determine the effect of adding milk and/or sugar, caffeinated or decaffeinated, instant or filter, on coffee’s cancer-protective potential. We also need to be sure that there are no harmful effects for any other conditions before making recommendations. That is why AICR cannot give specific advice about coffee.

Q. How should I barbecue, cook my burger and other meats to lower my cancer risk?

A: AICR does not provide advice about cooking methods on the whole because there is not enough evidence to do so. However, there is some evidence that shows charring or cooking meat at high temperatures over an open flame can produce substances [polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HCAs)] that are known to cause cancer. Because these cancer-causing compounds can contaminate food as it’s being cooked, we advise people to avoid eating burned or charred animal foods often or in large quantities. (AICR’s website also offers advice for minimizing the formation of these carcinogenic compounds, and for grilling plant foods, which does not produce PAHs or HCAs.)

Q:. How does soy relate to risk of breast cancer?

A: There is not enough evidence to make any specific recommendations about eating foods containing soy. However, there is an indication [limited-suggestive] that eating foods containing soy may improve survival after breast cancer. There is no evidence to suggest that soy foods are harmful.

More research is needed before AICR can offer any recommendation on eating foods containing soy for cancer prevention, however the soybean, a legume, is part of a healthy plant-based diet.

Q: Does sugar promote cancer growth?

A: There is no strong evidence to directly link sugar to cancer risk. However, foods that are high in added sugar also tend be high in fat and calories without being nutritious or filling. Eating high-calorie foods too often or in large quantities can lead to weight gain, and there is strong evidence that being overweight or obese increases the risk of 10 cancers. That is why AICR recommends eating a healthy diet that is rich in nutritious and filling foods, such as whole grains, vegetables, fruit and beans.

It's easy to consume large quantities of sugary drinks, such as soda and energy drinks, without feeling full. And because they are often high in calories, they can also lead to weight gain. It’s best to trade sugary drinks for healthier alternatives, such as water or unsweetened tea and coffee.

Q: Will artificial sweeteners increase my cancer risk?

A: There’s no strong evidence that links artificial sweeteners, such as saccharin and aspartame to cancer, so diet drinks sweetened with artificial sweeteners are one alternative to sugary drinks.

Q: Will vitamin D lower my cancer risk?

A: AICR is unable to advise people on vitamin D levels and cancer prevention. This is because there is no strong evidence of a link between vitamin D and cancer risk. However, vitamin D is an essential nutrient that plays an important role in calcium absorption and bone health. You get most of your vitamin D by exposing your skin to sunlight. Small amounts of vitamin D can be found in foods, such as sardines, meat and eggs, but fortified foods, such as milk and low-fat spreads are a better dietary source of vitamin D.

Certain people may benefit from taking vitamin D supplements: pregnant and breastfeeding women, babies and young children under the age of five, older people aged 65 years and over, people who are not exposed to much sun – such as people who cover up their skin when outdoors, or those who are housebound or confined indoors for long periods – and people who have darker skin, such as those of African, African-Caribbean and South Asian origin.

A: Research has shown that increase in blood sugar levels measured by glycemic load (GL) could have an impact on your risk of endometrial cancer.

Glycemic load looks at all the foods and drinks you consume over a day and measures the overall effect of your diet on your blood sugar levels. There is strong evidence that eating a diet that increases your blood sugar levels increases your risk of endometrial cancer.

More research needs to be done, but for now we recommend that people enjoy a balanced diet with plenty of plant foods, including whole grains, limit processed or sugary foods and avoid sugary drinks.

A: AICR/WCRF’s reports define processed meat as “meat preserved by smoking, curing or salting, or addition of chemical preservatives.” Ham, bacon, sausages, hot dogs and deli meats, are all considered processed meat. Watch One-Minute with the AICR Dietitian for more on processed meat and how to avoid.

The American Institute for Cancer Research is a nonprofit charity designated as tax-exempt under Section 501(c)3 by the Internal Revenue Service. Donations are tax-deductible to the full extent of the law. EIN 52-1238026.